export {}
// 1 + 1 * 2 = 3    (1 + 1) * 2 = 4
// let arr: (string | number)[] =[1,2,3,'张洪不要睡']

// let arr1: string | number[] = [123,333]

// 利用类型别名  type   推荐用大驼峰
type ItemType = (string | number)[]
type ItemType2 = string | number | boolean
let arr2: ItemType = [1,2,3,'老韩']

let item: ItemType2

let item2: ItemType2